A method for relaying packets through a relay node in a communication system composed of a source node, a destination node and at least one relay node for transferring the packets transmitted from the source node to the destination node. The relay node compares a potential corresponding to a number of hops and constituting the transferred packets with a stored potential from the destination node. If the stored potential is smaller than the potential constituting the packets, the relay node updates the packet and broadcasts the updated packets. Also, according to a method for setting a route for transmitting packets, packets are broadcast and it is checked whether updated packets obtained by updating the broadcast packets are received. If updated packets are received, an address of a packet transmission node constituting the updated packets is stored and the following packets are transmitted to the node having the stored address.